uv-photoemission spectra of ${\mathrm{CeSi}}_2$ have been measured with a resolution of 18 meV in the temperature range 15 K<T≤300 K. The spectral analysis has been performed within the Anderson single-impurity model using the noncrossing approximation and including 4f-spin-orbit and crystal-field splittings. It accounts perfectly for the observed flattening of the fine structures in the spectra when the temperature increases. This study confirms indisputably the many-body nature of the low-lying excitations around ${\mathrm{E}}_{\mathrm{F}}$ observed with photoemission.

• Received 2 February 1987

DOI:https://doi.org/10.1103/PhysRevLett.58.2810